While Arsenal fans implore their board to spend more, Manchester United manage finite resources far better. There was a mutinous feeling at the Emirates yesterday, directed at the board and the manager for failing to spend enough money on players.
Certainly, Arsenal do not have the muscle of Manchester City or Chelsea, through no fault of their own. But they were shown yesterday how, even in hard times, Sir Alex Ferguson has built a squad that can compete at the top.
Manchester United suffer from comparative under-investment too. Their midfield has needed revamping for years, although the reasons for their austerity are rather more complex than Arsenal's adoption of the "self-sustaining model".
But, despite circumstances, Ferguson's squad is deeper and more varied than Arsène Wenger's. The vigour of his young players, the nous of his older ones, and the improving alternatives he has on the bench all show a set of players unquestionably better equipped for elite challenges than Arsenal's.
While Wenger has been forced to run Aaron Ramsey into the ground in the last few months, the management of Ryan Giggs' workload is keeping him fresh. Giggs swiftly made it apparent to Ramsey yesterday that there is only room for one wily Welsh midfielder at the top end of the Premier League, and that the United player is rather keen that the role should continue to be his, for this season at least.
After half an hour, Ramsey was left static as Giggs drifted past him, before winning United a free-kick. When, nine minutes later, Giggs tried the same move again, Ramsey could only hold him back, and was booked. Giggs signed his first professional contract at United three weeks before Ramsey was born, but looked like he was the player with the gift of youth on his side.
When Giggs was in a dangerous space in the first half he delivered perfectly, onto the forehead of Antonio Valencia for United's first goal. Ramsey's final ball, from similar positions, was never as precise.
Danny Welbeck, though, just one month older than Ramsey, displayed none of his sluggishness. Ramsey has had to start 24 games for Arsenal so far this season, and Welbeck just 15. The United striker looked very obviously fitter and more energetic yesterday, with far deeper reserves now in the second half of the season.
Welbeck was a lively bounding presence throughout, holding up the ball and stretching Arsenal's defence as he tried to carve open space for Wayne Rooney. His runs in behind Per Mertesacker meant that Arsenal could never relax, and the German centre-back had to clear one off the line after Welbeck burst through and chipped Wojciech Szczesny. There seemed to be a push from Mertesacker on Welbeck, though the striker chose to take the shot.
"Danny's fantastic," Ferguson said afterwards. "His work-rate, movement all the time on the shoulder of the defender or ready to run through. Really he could have scored five, he was through four times. He's unlucky but he's got the important goal and has continued his run in the first team, that is up to nine goals or something like that. For a 20-year-old he's playing really well."
Welbeck's important goal came with nine minutes remaining, when Valencia squared the ball to him and he calmly slung a shot into the corner past Szczesny.
That was the moment when Arsenal fans felt vindicated in their fury at Andrei Arshavin's introduction: he meekly allowed Valencia to push past him in the build-up. Such a response to a substitution felt unique in English football, and betrays a remarkable lack of faith in the fringes of the first-team.
Ferguson, in contrast, was able to marshal his match-day squad to good effect. Rafael da Silva came on when Phil Jones went off with an ankle injury, and provided precisely the right combination of nerve and bite at right-back.
Then, with 14 minutes left, Ferguson thought Rafael had done enough and so turned to Park Ji-sung. Less gifted than Arshavin, certainly, but much more useful: Park received the pass from Valencia, and returned the ball, for United's winning goal. They have the squad, they had the options, and they took the points.